Logic X Please help) Static/white noise only in one project.

In a bit of a pickle here, I have white noise showing up in one project, but only that project, haven't had the problem with any of my many logic x projects - which I assume would rule out things like sound care, updates, firmware, speakers, cables etc.

I think it's probably being triggered by the audio (recordings) tracks, I know it's not in the audio, as you can mute all audio and the white noise signal is still there.

At one stage I was able to stack all audio tracks, mute stack . shut it all down , restart. You then start up project with only the midi instruments being audible,
no hiss, all good and then soon as you switch that stack off mute , hissing starts again . turn back on mute, still hissing there is no getting rid of it.

Thankyou in advance for any help or assistance you might able to share.